2. Field of the Invention
This invention relates to improvements in ink marking apparatus in general and to the print head operating mechanism, in particular of the type disclosed in prior U.S. Pat. No. 3,797,390, issued Mar. 19, 1974 and in presently pending U.S. application Ser. No. 254,396, filed Apr. 15, 1981 now U.S. Pat. No. 4,694,747.
According to prior U.S. Pat. No. 3,797,390, a print head is reciprocated between inking and marking positions by movement along a travel path established by a fixed cam track. During such movement, the print head is angularly reorientated for operative contact with a wet ink surface and a target on a work backing surface. Such arrangement was adopted and utilized in the marker apparatus disclosed in the more recent U.S. Pat. No. 4,528,908 to Davison et al. This same type of arrangement is also disclosed in the presently pending application aforementioned. The aforesaid type of ink marking apparatus has, however, been limited in use to imprinting on material undergoing intermittant travel, wherein print head contact occurs only while the material is momentarily stationary. For continuously moving target material, rotary print head arrangements have been developed as disclosed, for example, in prior U.S. Pat. No. 4,566,387. For such rotary print heads, inking rolls are utilized to indirectly transfer ink from a stationary ink storing cartridge in contrast to the direct transfer contact associated with the reciprocating and angularly reorientated type of print head aforementioned. Rotary print heads furthermore impose dimensional restrictions dependent on the diameter of the print cylinder and present problems in chaning type position.
It is therefore an important object of the present invention to provide an ink marking apparatus having the advantages associated with reciprocating and swingable print heads and yet having the flexibility of being adapted to the imprinting of continuously moving target material at rapid speeds.
Yet another object of the invention is to provide a marking device capable of being operatively installed with greater flexibility and less restriction, while providing easier access for both changing of the type and replacement of the ink storing cartridge.